It is known to use carboxymethylated cellulosic materials in situations where a high degree of exudate absorption is required. For example, WO 93/12275 describes the production of various absorbent products capable of absorbing many times their own weight of water. This causes the carboxymethylated fibers to form a gel. WO 94/16746 and WO 00/01425 describe the use of carboxymethylated Lyocell materials in wound dressings where the advantages of gel formation in preventing adherence and, therefore, reducing wound damage and pain on removal are discussed.
Known wound dressings comprising gel-forming fibers are essentially flat, rectangular and fairly small, typically 20 cm×15 cm. The usefulness of such dressings is limited with respect to sinus or cavity wounds due to difficulty in removing the dressing from such a wound. The gel-forming fibers gel on absorption of exudate and consequently lose tensile strength once in a gelled state. This presents a problem when the dressing needs to be removed as removal generally is done by pulling the ribbon out of the wound from one end of the ribbon. The loss of tensile strength means that the dressing fragments on removal and has to be removed in many pieces or by flushing.
However, it would be desirable to bring the advantages of gel-forming fiber dressings to cavity wounds by having the dressings available in a strip form with sufficient tensile strength to enable the dressing to be removed in one piece from the wound once it has gelled and to be removed in one piece regardless of which part of the dressing is grasped in the removal.
It is known to form ribbon dressings with a reinforcing scrim in order to improve the tensile strength of the dressing. There are, however, disadvantages in doing so. The scrim detracts from the absorbency of the dressing and can create a physical barrier to absorption. The scrim also renders the dressing opaque which means that the wound and surrounding skin cannot be observed once the dressing is in situ.
It is known to increase the tensile strength of bandages by stitching the bandage along its length with one or more lines of stitching. However, when longitudinal stitching is applied to a thin strip it gives strength only in the stitching direction and restricts how the dressing can be removed.